Electrical signaling system



Aug. 11, 1842. J. H. R. THOMAS ETAL ELECTRICAL SIGNALING SYSTEM FiledNov. 18, 1940 2 Sheets-sheet 1 F7; .1 IMP i T A0 a r T I w I br v C01 byw) INVENTORS JOHN HENRY RICHARD moms WILL/E SAWLLE 14 TTOI-PNEY J. H. R.THOMAS ETAL 2,292,978 ELIIJCTRICAL SIGNALING "sYsEEM Filed Nov. 18,3.940

2 Sheets-Sheet 2 FRB LP AL INVENTORS JOHN HENRY RICH/7RD THO/WIS WILLIES/W/LLE ATTORNEY Patented Aug. 11, 1942 UNITED STATES PATENT OFFICEELECTRICAL SIGNALING SYSTEliI Ware Application November 18, 1940, SerialN 0. 366,044 In Great Britain January 1, 1940 Claims.

The present invention relates to electrical signaling systems, and hasfor its object the provision of a centralised indicating system enablinginformation to be transmitted from a distant point by a simple operationsuch as dialling and displayed at a suitable control point. Such asystem is particularly suitable for use in air raid precautions serviceswhereby, for example, a number of divisional control posts in an areamay set up on an indicating board at a central or main control post adisplayed indication of the state of the personnel thereat in thevarious A. R. P. services such as first aid, decontamination, andauxiliary fire brigade, that is to say, the number of persons activelyengaged in each service and the number of persons in each serviceavailable for transfer to other divisions requiring them.

According to one feature of the invention, in an electrical signalingsystem for the transmission 1 of information over a line in response tothe operation of an impulse sender of the dial type, the initial digitis arranged to eifect the selection of the appropriate group ofindicating equipment which is all restored to normal on the commencementof the dialling of the succeeding digit and then operated to theappropriate setting by this and subsequent digits.

In a preferred system incorporating the invention a two-wire line, whichmay be an ordinary telephone line, connects the control centre to eachdivisional post at which is provided a telephone instrument and animpulse sending device comprising an automatic telephone dial. Each lineis terminated at the control centre in impulse-responding equipment ofthe automatic telephone type. The control centre is also provided withan indicating board which is preferably divided vertically into a numberof sections equal to the number of divisions in the area, each sectionbeing adapted to display the state of the various A. R. P. services inits corresponding division.

Assuming that provision is to be made for upto ten A. R. P. services andfor a personnel of up to ninety-nine for each service in each division,a five-digit dialling scheme will be required to communicate thenecessary information from a divisional post to the control centre. Thefirst digit dialled serves to select the indicating appa-.

ratus associated with the required one of the ten A. R. P. servicesprovided for and the succeeding four digits are received on thisapparatus, the first two serving to indicate the personnel available fortransfer to other divisions, while the last two digits indicate thepersonnel already on rescue work in the calling division.

If for example in division No. 1 there are five people available fortransfer and twenty-one at work in the first aid service, then the firstaid service indication in column 1 of the central indicator board willbe If there had been twenty available and six at work, then theindication would be Supervision is provided on the central stationequipment to guard against failure to dial the full complement ofdigits, and in these circumstances a delayed alarm is brought intooperation.

The invention will be better understood from the following descriptionof one method of carrying it into effect, reference being had to theaccompanying drawings comprising Figs. 1 and 2 which show a typicalcommunication and signaling iine between a divisional control centre anda main control centre and the circuits of the respending equipment andassociated supervisory equipment required at the main control centre foreach division.

The equipment shown is capable of handling up to ten A. R. P. services,although the indicating equipment for two services only is shown and itis capable of dealing with a personnel of up to ninety-nine in each ofthe services.

Considering now the operation, it is assumed that the divisional andmain control telephones DCT and MCT are of the magneto type and areconnected in the line by way of transformers TI and T2 respectively, thedivisional control centre being provided in addition with an automatictelephone dial having the usual impulse springs IMP and shunt oroff-normal springs It). The relay E and the key K for controlling itsoperation which are shown dotted will be disregarded for the present.

Assuming now that the condition of service No. l, which may be forexample first aid, is to be signaled and that there are five peopleavailable for transfer and twenty-one engaged on rescue work, the fivedigit number to be dialled When the dial is released, its impulsesprings IMP are momentarily opened once to send out one impulse andrelay AR extends a pulse to the magnet ADM of rotary switch A overarmature arl, wiper CI in position 2 and armature brB so that wipers Aland A2 are stepped to position 2. When the dial restores to normal, theoff-normal springs 10 re-open and relays AR, BR and CR release in turn.A further pulse is thereupon transmitted to magnet ADM so that thewipers Al and A2 are advanced a second step.

When the dial is again operated during the dialling of the second digit0, relays AR, BR and CR operate as before and step the C switch toposition 3 and during the operating time of relay CR, positive isextended over wipers C2 and. Al each in position 3 to energise therelease magnets |9-22 of the four indicating switches associated withcontact 3 on which wiper Al is standing. Wiper CI in advancing toposition 3 prepares an energising circuit for the indicator drivingmagnet ll, negative being connected thereto over armature 1114 and wiperA2 in position 3 when relay ER is energised.

It should be explained that for the purpose of indicating the state ofthe various services for each division, there will be provided for eachof the services a set of four indicating switches of the same mechanicalconstruction as the switches A and C, but without banks and wipers andinstead pointers or indicating drums. Assuming therefore that twoservices are to be provided for as shown in the drawings, then analteration to the display of service No. 1 will involve first anenergisation of the release magnets l922, whereupon the relevantindicating switches will be restored to normal, after which a suitabletrain of impulses will be delivered to each of the correspondingdriving. magnets I|-l4 in order to set up the new values. Similarly, forservice No. 2, release magnets 23-26 will first be energised, afterwhich a train of impulses will be delivered to each of the correspondingdriving magnets I5-I3. It will be appreciated that since the number ofimpulses transmitted to the driving magnets of the indicating switcheswill be in every case one more than the number dialled, the. setting ofthe pointers or indicating drums will need to be adjusted accordingly.

Returning again to the operation, when the dial is released andcommences to restore to normal, the train of ten impulses produced willbe extended to driving magnet ll. At the end of the train, relays AR, BRand CR will be released in the usual manner and an eleventh impulse willbe transmitted to magnet H. During the operation of the dial for thenext digit 5, the switch C will be stepped to position 4 so that thetrain of five impulses which will be produced will be extended to magnetl2 and so on.

When the. full complement of digits has been 'dialled, the switchmechanisms associated with the driving magnets H, I2, i3 and I4 willhave been set to display the numbers 05 21, and the control centre willthus be informed that in the first aid service for the division inquestion five people are available for transfer to other divisions andtwenty-one people are at work therein.

Considering now the restoration of the responding equipment to normal inorder that a signal corresponding to another service or another signalcorresponding to the same service may be sent in from the samedivisional control centre, it will be noted that on the release of relayBR with the wiper Cl in position 6, a cirsuit is completed over armaturebr3 for relay GR which accordingly operates. Thereupon at armature grlit energises the release magnets ARM and CRM of the switches A and C sothat these switches are restored to normal. The display set up on theindicator drums or the like is of course not affected.

The divisional control centre may now wish to indicate at the maincontrol centre a change in the state of the service No. 2 or to repeatthe information sent in previously in connection with this service, andthis will be done by dialling a five digit number commencing with thedigit 2 and followed by four further digits indicating the number ofpeople available and working. These four digits will be effective onmagnets l5, IS, IT and I8 of the four indicating switches associatedwith service No. 2, the release magnets 2326 being first operated torestore the switches to normal. Similar considerations apply to thesetting of the indicating switches relating to the other services whichare not shown.

It will be noted that when the switch C is advanced to position 2, relayCO is energised over wiper C2 and thereupon locks up at armature co I.Relay CO also at armature e02 prepares a delayed alarm circuit, atarmature co-3 lights the supervisory lamp LP, and at armatures 004 and005 opens points in the circuits of magnet TSM 0f the switch TS. Thisswitch is Of the wellknown reverse drive step-by-step type operatingalways in the same direction so that no release magnet is necessary. Thefunction of the switch is to time a suitable interval for instancetwenty seconds and control the giving of an alarm if a complete numberhas not been dialled within this time. It will be seen that the initialoperation of relay BR completes a circuit for the magnet TSM overarmature M5 and that when relay CO operates, this circuit is opened atarmature e04 whereupon the wipers TSITS4 are advanced one step, Acircuit is then completed over wiper TSI for the slow-to-operate relayFRA which at armature jral energise the similar relay FRB and atarmature fraZ energises the magnet TSM. Relay FRB at armature frbl opensthe circuit of relay FRA and the two relays therefore interact to stepthe switch TS. In normal circumstances, the complete number will havebeen dialled and relay GR will therefore be operated before the switchTS has stepped over the whole of its bank. Rela GR at armature 9T3releases relay CO and the switch TS is driven to its home position in aself-interrupted circuit over wiper T83 or T84, armature e05 andinterrupter contacts ts m. If the number is uncompleted however when theswitch wipers have made 49 steps the driving circuit is opened by wiperTSZ and over wiper T54 the alarm bell AL i operated. The switch TSremains in this position until an officer at the main control. centreoperates the reset key RSK which energises relay GR. This relaythereupon at armature grl energises the release magnets ARM and CRM ofthe switches A and C and at armature yrs releases relay CO whichthereupon over armature e completes the normal homing circuit forstepping the switch TS to position 1. It will be noted that at armaturegrZ relay FRB is held so as to prevent relay FHA from interfering withthe homing operation. The officer will also operate the hand generatorof the telephone MCT which may be individual to the calling line asshown, or may be connected thereto via a man .ually operate-d rotaryswitch, and thereupon rings the bell of the calling telephone DCT. Thedivisional control post will now be asked to repeat the codescorresponding to all the services thereat, this arrangement ensuringthat the display on the indicator board is brought completely correct.

In case the divisional control centre wishes to I initiate a telephonecall to the main control centre, the hand generator is operated in theusual manner and ringing current is applied to the line so as to ringthe bell of telephone MTG. Under these conditions relay AC, which isinoperative by direct current due to the condenser in series therewith,now operates and maintains the release magnets ARM and CRM 0f theswitches A and C energised so as to prevent any false operation occuringdue to accidental operation of relay AR by the ringing current Thecondenser shunting the off-normal springs Ill serves to complete thetalking circuit for telephone purposes.

frequent intervals signal to the main control centr the state of theirA. R. P. services so that an up-to-date indication of the rescue forcesavailable and at work in the various divisions of the area will bemaintained on the main control centre indicator.

Inplace of the magneto type telephones it may prove more satisfactory touse common battery automatic telephones, and in this case a telephonecall to the main control centre may be originated either by operating apress button which will send a distinctive signal over the line, oralternatively by dialling a distinctive first digit.

It will be appreciated that the system according to the invention iscapable of dealing with a larger number of A. R. P. services andpersonnel for the various divisions than has been described but in thiscase a greater number of digits will need to be dialled to set up therequired information on the central indicator board. It will also beunderstood that if desired the indicating switches might be providedwith wipers so as to operate lamps or other indicators not, suitable fordirect operation.

A further modification is possible to meet the case in which thepersonnel for a particular service never exceeds 9. In thesecircumstances a single digit would always be sufficient to transmit thedesired information and the dialling of two digits 0 represents waste oftime and effort. It may accordingly be arranged that in response to thedialling of a first digit representing a particular service for whichthe above conditions obtain, a circuit is completed for automaticallyadvancing the switch C from position 2 to a position 4 and then toposition 6 so that the three digits which are dialled are operative onthe correct magnets. This may conveniently be brought about by the useof an additional wiper and bank on each of the switches A and C. The Cswitch wiper would be connected to negative by way of a slow relay andcontacts 2 and 4 would be connected to the contact or contacts in the Aswitch bank corresponding to the digit or digits representing theservice in question. The A switch Wiper would then be connected topositive over a front contact of relay CR and a back contact of relayBB. in series. The slow relay would complete a circuit for the C switchmagnet. Accordingly at the end of the first digit and again at the endof the second digit, the additional relay would be energised for theslow release time of relay CR and would thus produce an extra step ofthe switch C. It will be understood that the indicators in the tensposition with preferably be fixed and give a permanent display of thedigit 0.

It may also be desirable to provide. facilities whereby a divisionalcontrol post may effect immediate cancellation if the operating partythereat realises he has transmitted an incorrect digit. The error couldbe disposed of by finishing the dialling of the live digit number oreven by dialling ls to give a total of five digits and then at oncetransmitting the correct five digit number. For rendering immediatecancellation possible however use may be made of the arrangement showndotted comprising relay E and the key K. Relay E is a differential relayhaving a winding in each side of the line and consequently is notaffected by the normal impulse sending operation. When the key isoperated, however, the lower winding only is energised and the relaythen operates and at its armature el energises the release magnets ARMand CRM of the A and C switches. This places the equipment in conditionto have the correct number dialled immediately.

We claim:

1. In a signaling system, a calling device of the type adapted to bemoved away from its normal positionand to transmit impulses during itsreturn to normal, off-normal contacts on said calling device operatedwhenever the movement of said calling device away from its normalposition is initiated, a plurality of devices for receiving saidimpulses transmitted by the dial during its return to normal, and meanscontrolled by said off-normal contacts upon each movement of said dialaway from its normal position to con dition a different one of saidreceiving devices to respond to the impulses transmitted by said callingdevice during its next return to normal.

2. In a signaling system, a calling device of the type adapted to bemoved away from its normal position and to transmit impulses during itsreturn to normal, an off-normal contact on said calling device operatedwhenever said calling device is moved away from its normal position, anautomatic switch, means controlled by said off-normal contact foroperating said switch once for each movement of said calling device awayfrom its normal position, a plurality of receivers, a wiper on saidswitch effective to connect up a different one of said receivers uponeach operation of said switch, and means for repeating over said wiper,to the receiver connected up, the impulses transmitted by said callingde vice during each return thereof to normal.

3. In a signaling system, a dial adapted to be moved away from itsnormal position and to transmit impulses during its return to normal,

oif-normal contacts on said dial operated when the movement thereof awayfrom normal is initiated, said contacts being maintained operated untilthe return of said dial to normal is substantially complete, anautomatic switch, means controlled by each said operation of saidoff-normal contacts for transmitting to said'switch an impulse ofuniform length regardless of the length of time said contacts remainoperated, thereby to operate said switch once for each movement of saiddial away from its normal position, a plurality of receivers, a wiper onsaid switch eifective to connect up a different one of said receiversupon each said operation of said switch, and means for repeating oversaid wiper, to the receiver connected up, the impulses transmitted bysaid dial during each'return thereof to normal.

4'. In a signaling system, a calling device of the type adapted to bemoved away from its normal position and, during its return to normal, totransmit any digit in the form of a train of impulses, an off-normalcontact on said calling device operated whenever said calling device ismoved away from its normal position, a register having any digitregistered therein, means controlled by said off-normal contact uponoperating when said calling device is moved away from its normalposition to restore said register to normal thereby to cancel the digitregistered therein, and means then controlled by said calling deviceduring its return to normal to register in said register the digittransmitted by said dial during such return.

5. In a signaling system, a calling device variably operable to senddifferent digits, a plurality of registers each corresponding to adifferent digit, an automatic switch having access to all of saidregisters and controlled by said calling device in accordance with thedigit sent by it on a first operation thereof to select the one of saidregisters which corresponds to that digit, means in the selectedregister controlled by said calling device, when next operated, tocancel whatever digit is already registeredin said selected register,and other means in said selected register controlled by said nextoperation of said calling device to register therein the digit sent bysaid calling device upon said next operation thereof.

6. In a signaling system, a calling device variably operable to senddifierent digits, a plurality of groups of registers, each groupcorresponding to a different digit, an automatic switch having access toall said roups of registers and controlled by said calling device inaccordance with the digit sent by it upon a first operation thereof toselect the one of said groups corresponding to that digit, meanscontrolled by said calling device, when next operated, to restore all ofthe registers in the selected group to normal, thereby to cancelwhatever digits are registered in said registers, means in one of theregisters of the selected group controlled by said next operation ofsaid calling device to register the digit sent by said calling deviceupon said next operation, and means controlled by each additionaloperation of said calling device to register the digit sent by saidcalling device upon that operation in a difierent one of the register ofsaid selected group.

7. In a signaling system as claimed in claim 6, a timing device, meansfor automatically starting said timing device to operate upon said firstoperation of said calling device, and means thereafter controlled bysaid calling device to give an alarm if said calling device is notoperated a predetermined number of times within a certain interval aftersaid timing device is started.

8. In a signaling system, a plurality of indicators, a variably operablecalling device, a switch having access to all of said indicators andcontrolled directively by said calling device, when first operated, toselect any desired one of said indicators, means in the selectedindicator controlled by said calling device, when next operated, torestore said indicator to normal thereby 'to cancel the indicationpreviously existing in said selected indicator, and other means in saidselected indicator controlled by said next operation of said callingdevice to produce in said indicator a new indication varying inaccordance with the way said calling device is operated upon said nextoperation thereof.

9. In a signaling system, a plurality of receivers, a switch havingaccess to all of said receivers, a calling device operated todirectively control said switch to select any desired one of saidreceivers, a movable element in the selected receiver, at least threepositions which said element may occupy, said element occupying any oneof said positions at the time said receiver is selected, and meansthereafter controlled by another operation of said calling device formoving said element from the position occupied by it at the time saidreceiver is selected to any other one of said positions.

10. In a signaling system, a plurality of receivers, a switch havingaccess to all of said receivers, a calling device operated todirectively control said switch to select any desired one of saidreceivers, a movable element in the selected receiver, a normal positionand a plurality of different off-normal positions which said element mayoccupy, said element occupying any one of said off-normal positions atthe time said receiver is selected, and means controlled by anotheroperation of said calling device for thereafter moving said element fromthe position occupied by it at the time said receiver is selected tosaid normal position and for then moving it from said normal position toany desired one of said oif-norma1 positions.

JOHN HENRY RICHARD THOMAS. WILLIE SAVILLE.

